Work out video file size from bitrate instantly with clear inputs, formula shown and shareable results.
File size is bitrate times duration divided by eight to convert bits to bytes, with the audio stream added at its own bitrate. The divide-by-eight step is where estimates usually go wrong, and it is why a 50 Mbps codec fills 375 MB every minute rather than 50.
File size
megabytes = bitrate in Mbps x seconds / 8
With audio
add audio kbps x seconds / 8000 megabytes
megabytes = bitrate in Mbps x seconds / 8. File size is bitrate times duration divided by eight to convert bits to bytes, with the audio stream added at its own bitrate.
The divide-by-eight step is where estimates usually go wrong, and it is why a 50 Mbps codec fills 375 MB every minute rather than 50.
Enter bitrate, duration, audio bitrate. The defaults shown are a realistic worked example — swap in your own figures to get a result you can use.